10.2190/CX0W-YBKY-NWN0-1943 CX0WYBKYNWN01943 1 Automobile Fuel Use and Conservation 85 95 20020509 20020509 20020509 20020509 CX0WYBKYNWN01943.pdf http://baywood.metapress.com/link.asp?target=contribution&id=CX0WYBKYNWN01943 2 Eric Hirst Research Engineer, ORNL-NSF Environmental Program, Oak Ridge National Laboratory, Oak Ridge, Tennessee <p>Variations in automobile fuel economy as functions of trip length and of driving conditions (urban and inter-city) are calculated for subcompact, "average," and full-size cars. Fuel economy is considerably worse for urban driving than for inter-city driving because of cold-start operations and frequent stop-and-go cycles for urban driving. Fuel economy improves markedly with increasing trip length because the adverse impact of cold start is spread over more miles. Subcompacts achieve much better fuel economy than do full-size vehicles under all conditions; this is especially so for urban driving.</p><p>A number of strategies exist that could be used to conserve fuel by discouraging short auto trips and by discouraging the use of large cars. These strategies include: shifts from automobiles to public transit, shifts from automobiles to bicycles for short trips, shifts from full-size to subcompact automobiles, increases in automobile occupancy, and reductions in the overall level of automobile travel.</p> U. S. Federal Highway Administration, <i>Highway Statistics/1971</i>, 1972; also, <i>Highway Statistics Summary to 1965</i>, 1967. W. Dupree, Jr. and J. West, <i>United States Energy Through the Year 2000</i>, U. S. Department of the Interior, December 1972. E. Hirst, <i>Energy Intensiveness of Passenger and Freight Transport Modes: 1950-1970</i>, Oak Ridge National Laboratory Report ORNL-NSF-EP-44, April 1973. R. Husted, "Mass Transit Impact on Energy Consumption," Society of Automotive Engineers Paper 730521, New York, N. Y., 1973. P. J. Claffey, <i>Running Costs of Motor Vehicles as Affected by Road Design and Traffic</i>, National Cooperative Highway Research Program Report 111, Highway Research Board, 1971. C. E. Scheffler and G. W. Niepoth, "Customer Fuel Economy Estimated from Engineering Tests," Society of Automotive Engineers Paper 650861, New York, N. Y., November 1965. E. Hirst, <i>Direct and Indirect Energy Requirements for Automobiles</i>, Oak Ridge National Laboratory Report ORNL-NSF-EP-64, February 1974. U. S. Federal Highway Administration, <i>Nationwide Personal Transportation Study</i>, Report 1—Automobile Occupancy, April 1972. Motor Vehicle Manufacturers Association, <i>1972 Automobile Facts and Figures</i>, Detroit, 1972. Consumers Union, <i>Consumer Reports</i>, several issues in 1971 and 1972. G. J. Huebner, Jr. and D. J. Gasser, "General Factors Affecting Vehicle Fuel Consumption," presented at 1973 Society of Automotive Engineers National Automobile Engineering Meeting, Detroit, May 15, 1973. T. C. Austin and K. H. Hellman, "Passenger Car Fuel Economy-Trends and Influencing Factors," Society of Automotive Engineers Paper 730790, New York, N.Y., September 1973.